When a good is shipped, damage may occur to the good if the package in which the good is carried is subjected to a large force, for example, by being dropped, if the package is exposed to extremes in temperature and/or humidity, if the package is exposed to certain chemicals such as nicotine or carbon monoxide, radiation including visible or invisible light, or if the package is tampered with. Some goods may be particularly susceptible to damage from external forces or environmental extremes. For example, glassware, electronic instruments, mechanical parts, and the like may be damaged if dropped or subjected to excessive acceleration. Similarly, electronics, liquids, and pharmaceuticals may be harmed if exposed to temperatures and/or humidity outside of predetermined ranges.
Further, damage to a good may not be apparent simply by inspecting the good. Exposure to forces or extremes in temperature may not cause visually perceptible changes, but may affect the operating characteristics, effectiveness, and/or longevity of the good. For example, the effectiveness of the pharmaceutical may be altered if such pharmaceutical is exposed to extreme temperatures. Similarly, electronic boards in a device may become unseated from connectors if such device is subjected to excessive acceleration, as may occur from being dropped or jostled.
In addition, when a recipient reports to a sender that the good was damaged in transit, it may be difficult to ascertain when during transit the damage occurred, and who is accountable for such damage. Further, it may be difficult to confirm whether the damage to the good occurred during transit or after the good was received by the recipient.
Monitoring devices have been developed that can track the progress of a good during shipment. Such monitoring devices typically include a processor, memory, one or more sensors, and a Radio Frequency Identification (RFID) transceiver. Such a device may include an accelerometer to measure any forces acting on the device, or an environmental sensor that measures, for example, the temperature and/or humidity in the environment surrounding the device. Such a device may be affixed to a package to be shipped, and a processor in the device periodically polls the one or more sensors to acquire therefrom measurements associated with forces acting on the package and/or the environmental conditions. The processor then records such measurements and a timestamp of when such measurement was acquired in the memory associated with the RFID transceiver. An RFID reading device may later be used to read a log of measures associated with the forces and environmental conditions encountered by the package to which the monitoring device was affixed. Such log may be analyzed to determine if the package encountered extraordinary forces and/or environmental conditions.
In the monitoring device described above, the processor is powered and becomes active periodically to poll the sensors in the device. Such a device may require a battery with sufficient capacity to allow the processor to become active many times while the package is in transit. A battery that has sufficient capacity may be bulky and may add to the cost of the device. Because the processor remains active, heat sinks may also have to be used to draw heat away from the monitoring device and the package. Because of these considerations, such devices may be larger, heavier, and more expensive to be used routinely.